Modern field irrigation machines are combinations of drive systems and sprinkler systems. Generally, these systems are divided into two types depending on the type of travel they are designed to execute: center pivot and/or linear.
Regardless of being center pivot or linear, common irrigation machines most often include an overhead sprinkler irrigation system consisting of several segments of pipe (usually galvanized steel or aluminum) joined together and supported by trusses, mounted on wheeled towers with sprinklers positioned along its length. These machines move in a circular pattern (if center pivot) or linear and are fed with water from an outside source (i.e. a well or water line).
Most irrigation systems today are driven by an electric motor mounted within one or more drive towers. For most of these irrigation systems, the terrain needs to be reasonably flat. Recently however, these systems have been become more ruggedized and are increasingly used in undulating country. This advantage has resulted in increased irrigated acreage and water use in some areas. In these environments, however, irrigation systems have an increased tendency to “coast” or slip when then are stopped or slowed on sloped surfaces. This results in unwanted and uncontrolled movement by large spans of machinery. Further, it results in the time-consuming misalignment of irrigation spans.
Various braking methods have been applied to irrigation machinery. For instance, U.S. Pat. No. 7,073,638 teaches an agricultural irrigation system which includes a ball ramp brake set between a drive gear motor and a divider gear box. Similarly, U.S. Pat. No. 8,215,471 teaches a mechanical brake for use as torque blocker in an actuator drive which includes an axial shifting mechanism arranged on an input drive shaft. Still further, U.S. Pat. No. 3,957,144 teaches a continuous roller brake for a mechanical actuator which has a ball element engaging in a circumferential groove. While helpful, none of the prior art systems teach or suggest an irrigation system braking mechanism which prevents an irrigation system from coasting after the system has been shut off or when it is in idle.
Based on the foregoing, the present invention provides a system and method for providing drive shaft braking for an irrigation machine. The present invention overcomes the short comings of the prior art by accomplishing this critical objective.